In general, as eyeglass frames, a rim frame (full rim), a two-point frame (rimless frame), a grooved frame (half-rim and Nylor) and the like are known.
As a two-point frame in theses eyeglass frames, a two-point frame disclosed in JP 2005-275190A is known. As this two-point frame, two-point frame eyeglasses 100 illustrated in FIGS. 30A, 30B, for example, are known. In this two-point frame eyeglasses 100, a bridge (an attachment for a two-point frame) 101 is arranged between nose sides of right and left eyeglass lenses ML, MR, the bridge 101 is fastened to the eyeglass lenses ML, MR by fastening screws 103, 104, and attachments 105, 106 (attachments for a two-point frame) for attaching temples 109, 110 are fastened by fastening screws 107, 108 on ear sides of the eyeglass lenses ML, MR. In addition, the temples 109, 110 are attached to the attachments 105, 106.
In order to fasten the attachment 106 to the right side eyeglass lens MR by the fastening screw 108 as illustrated in FIG. 30C, it is necessary to form an attachment hole 109 on the eyeglass lens MR as illustrated in FIG. 30D. Moreover, in order to fasten the bridge 101 on the nose side of the eyeglass lens MR by the fastening screw 104, it is necessary to form an attachment hole 110 as illustrated in FIG. 30E.
The attachment 106 for fitting a temple includes a side plate portion 106a which has contact with an ear side portion of the circumferential face of the eyeglass lens MR and a fastening plate portion 106b which has contact with an ear side portion of a rim portion of a front side refracting face fr of the eyeglass lens MR. An angle between the side plate portion 106a and the fastening plate portion 106b of the attachment 106 is set to α.
Meanwhile, when manufacturing the above-described two-point frame eyeglasses 100, it is general for a person wearing eyeglasses to measure refracting power and check a visual performance of eyes and also to select an eyeglass frame in an eyeglass shop. In an eyeglass shop, it is general to display eyeglasses in which a lens such as a demo-lens (dummy lens) is fitted in a frame.
Even in two-point frame eyeglasses, the above attachment 101, 105, 106 and the like are fitted in a demo-lens (dummy lens). Moreover, the position of the mounting hole 109 into which the attachment 106 is fitted is the same as the position in actual eyeglasses. For this reason, it is necessary to measure the position of the attachment hole 109 into which the attachment 106 is fitted. This is the same as the bridge 101, the attachment 105 and the like.
As a method of measuring a position of such a mounting hole 109, a method of obtaining a shape of a lens and a mounting hole from output of a light receiving element by projecting parallel illumination light flux from one face of a lens and receiving the light flux which has transmitted the lens and the light flux around that by the light receiving element as described in Spanish Patent Application No. 2006-00589.
However, the mounting hole is formed to be inclined to a lens. For this reason, the projection positions to the light-receiving element of the opening of both ends of the mounting hole are overlapped out of alignment, and the inside opening of the mounting hole and the opening on the side into which the illumination light enters are reflected by the lens to be projected on the light-receiving element; thus, the position of the mounting hole can not be accurately measured.
It is, therefore, an object of the present invention to provide a lens shape measuring device which can easily and accurately measure a position of a mounting hole for fitting an attachment of a two-point frame into a lens.